PHYSMOD_ ULTRASOUND & SHOCKWAVE

Sound with a frequency greater than 20,000 cycles per second (Hz) that, when applied to the body, has thermal and non-thermal effects.

Sound with a frequency greater than 20,000 cycles per second (Hz) that, when applied to the body, has thermal and non-thermal effects.

ULTRASOUND ( Deep heating modality)

• Human ear can hear sound in this frequency range: 16-

  20,000 Hz

US ANATOMY:

• ________: usage depends on the size of the target area

  • _____ diameter - very localized; small areas

  • _____ diameter - for large areas (eg. back)

• Piezoelectric crystal

• ○  ______ location of piezoelectric material

• ○  Effective radiating area

• ○  _______ - passageway of electricity alternating

  current

•  Transducer Head

  • small

  • large

• Front Plate:

• Coaxial cable

GENERATION OF US

• Produced by_______ effect through the application of high frequency ____ to a ______ crystal

• This material expands & contracts in response to AC

• When the crystal expands, it ______ the material

  in front of it; when it contracts, it ______ the material.

• The alternating ______ - ________ is the ultrasound

  wave

________ - Most-commonly used, inexpensive but efficient

Reverse piezoelectric

• AC → piezoelectric crystal

• COMPRESSES → RAREFIES

• compression-rarefaction

• Plumbium zirconium titanate (PZT) → others: quartz, barium

  titanate
  

US

• Enters the body and is attenuated in the tissue by _____, _____, and ______ (critical angle: ___°)

______ is Decreasing US intensity as the wave travels through tissues. Greatest in tissues with high _____ content and with the use of high US frequencies.

• absorption, reflection & refraction → 15°

• attenuation → collagen ( INC attenuation)

Generation of US

Fresnel Zone

• ______ (near transducer head)

• Absence of ______

  • Sound is concentrated

• _____ & _____ are close to each other Length of near field depends on diameter of the treatment head

• Near field

• divergence

• Maxima (compressed ) and minima ( expanded)

Generation of US

Fraunhofer Zone

• ______ (far from transducer head)

• Nearly absent _______ which gradually ______ with increasing distance to the transducer

• Ideal : _________

• Practical application: _____ technique

• Far field

• interference , decreases

• near part of the far field

• underwater

Best distance for targeting a body tissue/tendon/ligament/ fascia (high collagen content) should be in ____ the _________ & ______

• Best sound wave

• Not too converge or diverge

T or F:

(1) US is ideal for muscles especially during muscle spam,guarding

(2) US heats smaller, deeper areas compared to superficial heating agent

• between the Fresnel and Fraunhofer zones

• False, not ideal → low absorption coefficient

• True

T or F:

(1) US must be perpendicular and in contact with the surface area . If transducer head loses contact with the skin, US reflects outside the area

(2) Metal implant is a contraindications for US

True

False, does not absorb US

US EFFECTS: THERMAL

• ↑ _______ rate

• ↑ _______ velocity

• ↑ _____ flow

• ↑ _______ extensibility

• Reduction of _____ & ____

• Metabolic rate

• NCV

• blood flow

• soft tissue extensibility

• pain & spasm

US EFFECTS: NON - THERMAL

• ↑________ permeability

• ↑ intracellular_____ & _____ release

• ↑ rate of _________ by ______

• Promotes _________

• Inhibits _________

• _______ streaming

  • Steady, circular flow of cellular fluids induced by US

  • Main non-thermal mechanism

• _______

  • Microscopic movement or oscillations of body fluids and tissues induced by US

  • Unidirectional movement of fluids along the

    boundaries of cell membranes resulting from the mechanical pressure wave in a US field

• _______

  • Formation, growth, and pulsation of gas-filled

    bubbles of US, which expand and compress d/t ultrasonically induced pressure changes in tissue fluids

• cell membrane

• Ca+ ions & histamine

• protein synthesis by fibroblasts

• macrophage responsiveness

• muscle atrophy

• Acoustic streaming

• Micromassage

• Cavitation

US Indications

____________

• For reduction of pain

  • Gate Control Theory

  • Relaxation of muscles - breaks pain muscle cycle

  • Vasodilation - washes away inflammatory cells; deposits Oxygen and nutrients

• Before stretching shortened soft tissues

  • Due to immobility, inactivity or scarring; TO INC ROM

____________

• To acccelerate tissue healing

  • Dermal ulcers, surgical skin incisions,tendon injuries & bone fractures

• Phonophoresis

  • transdermal drug delivery ( penetration ng drug sa skin)

Thermal/ Continuos US

Non Thermal / Pulsed US

US Application Parameters

• Frequency → _______

• Intensity → _______

  • Beam non-uniformity ratio (BNR)

• Duty cycle → _____

• Treatment duration → ______

• Effective radiating area → _______

  • Size of transducer head

• Mhz

• W/cm2

• BNR

• %

• mins

• ERA-cm2

US FREQUENCY

Higher temperatures are achieved in tissues with high collagen content and with the application of high frequency US.

3 MHz versus 1 MHz

• Depth of penetration is lower in ____ MHz

  • Attenuation happens in higher frequencies → does not reach deeper structures

  • Near field of 3 MHz is too close and concentrated → temperature quickly _____

    • A high frequency must be partnered with a ____ intensity.

• Maximum temperature achieved is higher in __ MHz

Depth of Penetration

• 3 MHz:_____ cm deep

• 1 MHz: up to ____ deep

• 3

• rises

• low

• 3

• 1-2cm; 5cm

US FREQUENCY

The US energy attenuates as it travels through soft tissue. At 1MHz, the energy can penetrate to the deeper tissues although the beam diverges slightly. At 3 MHz, the effects are primarily in the superficial tissues and the beam is less divergent.

(b) In the near field, the distribution of energy is non-uniform. In the far field, energy distribution is more uniform but the beam is more divergent.

US DUTY CYCLE

• percentage or ratio of the pulse duration to the pulse period

• Formula : ________

• For Thermal effects:

  • ______% (_____) duty cycle

  • If on time is equivalent to on + off time

• For non-thermal effects

  • ________ duty cycle

  • Used in ______ mode

  • Usually ____ duty cycle; then increase duty cycle as the pt progress from acute stage to reach _____ duty cycle

• DC = Duration of pulse (on time)/ pulse period ( on + off time)

• 100 % → continuous

• Less than 100% → pulsed

• 20% → 100%

US DUTY INTENSITY

•  Patient’s report of warmth is used to determine intensity when thermal US is applied.

• Intensity: ___________

• ________ is the ratio of spatial peak intensity to the spatial

  average intensity

  • If BNR is 6:1, when the spatial average intensity is

    _______ , the spatial peak intensity could be as high as _____

High intensity can cause burns or hotspots; reason why the head is moved around the area during US treatment.

• Machine is set to the ________ intensity

• mild warmth ; cooler sensation than HMP

• Beam non-uniformity ratio (BNR)

  • 1.5 W/cm2 = 6:1

  • 9 W/cm2

• spatial average intensity

US DUTY INTENSITY

For Shortened Soft Tissues

• _______ W/cm2 when 3 MHz is used for 5 - 10 mins.

• _______ W/cm2 when 1 MHz is used for 5 - 10 mins.

  • Stretching is recommended to be applied during heating and maintained for ______ mins after US.

  • If condition is tightness or contracture and PT has many interventions and/or exercises, it is ideal to do US before stretching.

• 0.5–1.0 ; 1.5–2.5

• 5-10 mins

US DUTY INTENSITY

For Painful Areas

• ______ W/cm2, 1 or 3 MHz for ___-10 mins.

  • for superficial area → MHz ,___ W/cm2

  • for deep area →____ MHz , ____ W/cm2

    • Start from 1 - 1.5 W/cm2 gradually increasing towards the end-range

    • If frequency is high, start at lower intensity

    • If frequency is low, intensity can be

      increased

• Acute pain → ___ mode

• Subacute / Chronic pain → ____ mode

• 0.5–3.0 → 3- 10 mins

  • 3 MHz , 0.5 W/cm2

  • 1MHz , 3.0 W/cm2

• pulse

• continuous

US DUTY INTENSITY

For Wound Healing

• _____ W/cm2, ___ MHz, ____% duty cycle for___ - 10 mins.

  • Pulse mode, superficial and low intensity

  • Around wound perimeter or using ____ over the wound or ____ technique or using _____ technique

• 0.5–1.0, 3mHz, 20% for 3-10 mins

• direct, coupling sheet, glove or underwater can be used

US DUTY INTENSITY

• For tendon & ligament repair

  • Acute: ______ W/cm2, ____ MHz, ____ mode

    • To accelerate tissue healing

    • It is recommended that US is applied in a low

      pulse mode at low intensity (0.5 to 1.0 W/cm^2) during the acute phase of tendon inflammation to minimize the risk of aggravating the condition and to accelerate recovery

  • Chronic: _______ intensity to increase tissue temperature, ____ mode

    • To address tissue shortening (tightness or

      contracture)

    • It is recommended that continuous ultrasound at high enough intensity to increase tissue temperature be applied in combination with stretching to assist in resolving chronic tendonitis if the problem is accompanied by soft tissue shortening due to scarring

• 0.5–1.0, 1 or 3 , pulsed

• high intensity → continuous mode

US DUTY INTENSITY

• For bone fractures

  • Very low dose US

  • ___ W/cm2, ___ MHz, ___% duty cycle for ____ mins.

• For Carpal Tunnel Syndrome

  • ____ W/cm2, 1 MHz, ____ mode 1:4 for ___ mins.

  • glove or underwater technique and only treating the attachment of the carpal ligament; to avoid the median nerve

• For Phonophoresis

  • _____ W/cm2, ___ MHz, ___% duty cycle for ____ mins.

  • low intensity, ____ mode

  • Therapists should be aware drugs delivered by phonophoresis are initially more concentrated at the delivery site, they are quickly distributed around the body by the vascular system.

    • tendinitis, tenosynovitis, and carpal tunnel syndrome.

• 0.15 → 1.5 → 20 → 15-20mins

• 0.5–1.0 → 1 → pulsed → 5-15

• 0.5–1.0 → 3 → 20 → 5-10

  • low intensity, pulsed mode

US TREATMENT DURATION

• Usually ____ mins. for each treatment that is 2x the Effective Radiating Area (ERA)

  • Area 20cm2 , ERA of 10cm2 = _____

  • Area 40 cm2, ERA of 10 cm2 = ______

• Duration is generally increased when:

  • Lower _____ or lower _____ are used

    • i.e. bone fractures

  • Areas _____ than twice ERA

  • _____ effects are desired

• 5-10

• 5-10mins ; 10-20 mins.

• intesities/frequencies

• larger than twice ERA

• heating effect

Methods of Application

• ______ Method

  • ______ method is ideal and commonly used to prevent hot spots and spatial peak

    intensity

  • If target is super localized, ______ method can be used

  • Rate : _______ or 2-8cm ; circular or vertical motion

• _______ Technique

  • glove with water over the treatment area separating it from the US head

  • Useful for irregular surface areas (E.g. fingers, malleolus)

• _______ treatment

  • Degassed water is required since bubbles can affect the transmission of US waves

  • messy method of application

    • For pts who can not position properly, distal extremities and circumferential treatment areas

      • E.g. hands, fingers, toes, ankle

Direct Method

• Moving

• Stationary

• 4cm/sec

Glove/Balloon Method

Underwater Treatment

Supplementary

• Applying HMP before US

  ● Can ↑ temperature of skin and subcutaneous tissue (1-2mm) while not affecting deeper tissue layers

  ● HMP only targets superficial structures; until subcutaneous tissues only
  ○ For pain and inducing muscle relaxation

  ● US can target muscles, tendons, ligaments, capsules; HMP can precede US treatment
  ○ For ↑ tissue extensibility of deeper tissues

• Applying cryotherapy before US

  ● Can decrease temperature of skin, reducing the effect of heating by US

  ● Decreases sensation; therefore, exercise caution on US use

  ○ Decrease in NCV causing numbness = decreased sensation

  ○ Patient report of warmth is the gauge for intensity ● We do not apply US after application of cryotherapy.”

  - D1

US Contraindications

• Malignant Tumor

  • consult MD if pt has hx of cancer within the past 5 years

• Pregnancy

  • on the hip, low back → baby heat sheesh

• CNS tissue

  • craniotomy, laminectomy

• Joint cement or plastic components of arthroplasty

  • it would heat up

• Pacemaker

  • can be applied distant to the pacemaker - 6 inches

• Thrombophlebitis

• Eyes

• Reproductive Organs

  • baog ka boi

US PRECAUTIONS

• Acute Inflammation

  • Use Pulse Mode

• Epiphyseal plates

  • Low dose US only

• Fractures

  • very low dose → longer duration

• Breast Implants

  • low dose only

Precautionary measure: swab US head and gel bottle heads with disinfectant to reduce level of contamination

Adverse Effects

• Burn

  • Occur when high-intensity, continuous US, and

    stationary technique is used

  • Do not apply thermal level US to areas with

    impaired circulation or sensation

• Blood cell stasis

  • US standing waves causes a collection of gas bubbles

    and plasma at antinodes and collections of cells at nodes; accompanied by damage to the endothelial lining of the blood vessels

• Cross Contamination & Infection

Documentation

1. US duty cycle

2. US frequency

3. US intensity

4. Treatment duration

5. Area of the body to be treated

6. Patient position

7. Method of application

8. Goal or rationale of treatment

Example:

Cont. US X 1 MHz X 1.5 W/cm2 X 5 mins on the anteroinferior aspect of (L) shoulder (abducted 90° & externally rotated) in supine using direct method to inc tissue extensibility.

Phonophoresis using V-gel using small head X 3 MHz X 1.0 W/cm2 x 20% duty cycle X 5 min on L lateral epicondyle in short sitting c L arm on the table using bladder method to dec. pain.

Shockwave Therapy

• _________ ( ESWT)

• Compressed air goes out of the transducer head; vibrates

  metal at tip of head

• Introduction of high-energy sound waves

  • SWT to Rotator Cuff Muscles in patients with

    Rotator Cuff tendinitis (there are calcium deposits that need to be disintegrated to facilitate healing)

• Use of _____ -impulse, focused acoustic sound waves with

  rapid rise in _____

  • Audible and loud high energy sound waves/impulses

  •  Successful therapy is dependent upon concentration

    of the shock wave’s focus

  • Location of the maximum peak positive pressure is the focus of the shock wave

• Extracorporeal shock wave therapy (ESWT)

• single impulse focused acoustic sound waves with rapid rise in pressure
  

Shockwave Therapy Mechanisms

• ______

  • Works like a spark plug, ignition

• _________

  • Produces magnetic fields to produce shockwave

• _________

  • Electrical to mechanical energy (acoustic

    sound waves)

  • Similar to ultrasound

• Electro-hydraulic

• Electromagnetic

• Reverse piezoelectric

Shockwave Therapy

• Because the pulse duration of the shock wave is extremely short( ____ μs) and is generated at low frequencies (audible unlike US), it is minimally absorbed by the tissues and therefore NO ______ is generated.

• It is a noninvasive but powerful treatment providing a deeper penetration of up to ____ mm of human tissue, which is deeper than that of conventional ultrasound therapy.

  • Often just done _ x a week, _ weeks/sessions total

The treatment region must be targeted via ultrasound or fluoroscopic x-ray imaging devices to ensure the energy is focused to an accurate location.

• (3 to 5 us)

• no thermal effect

• 50

• Once a week or SWD for 3 sessions only

Shockwave Therapy

Intensity: _______ (mJ/mm^2)

• Energy Flux Density is the total energy of a treatment which includes the number of shock impulses and the energy density known as energy per square area (_____)

Duration : ______

• Low, Moderate, High

• mJ/mm^2

• ~ 30 mins

Shockwave Therapy Physiologic Effects

• Disintegrating ____ deposits

  • For patients with Rotator Cuff (Calcific) Tendinitis

• ______ analgesia

  • For pain relief

  • Because of hyperstimulation → mechanical energy /

    vibration / micromassage effect

  • Gate Control Theory = mechanoreceptors are

    stimulated → C fibers are blocked

• ______

  • Like “applying” trauma / introducing microtrauma using shortwave diathermy → stimulates body to heal itself → forms new blood vessels → blood supply improves (O2 & nutrients)

• Changes in ______

  • O2 & nutrients will enter → better healing process

• calcium

• Hyperstimulation

• Neurovascularization

• cell permeability

ST INDICATIONS

• Introduction for 3-5 sessions once a week showed improvement in condition

• Chronic plantar fasciitis (with or without heel spur)

  • Most common

• Calcium tendonitis of the rotator cuff

• Lateral epicondylitis (Tennis elbow)

• Achilles tendinopathy

• Chronic foot ulcers, either diabetic or nondiabetic ● Osteoarthritis of the knees

• Management of nonunion fx

• Other Msk Disorder

Side Effects

• Hematoma

• Reddening

  • Due to neovascularization so we can expect redness

• Petechiae

  • Tiny red dots due to microtrauma, capillaries burst and blood escapes

  • Attributed to the effect of shock waves on gas-filled hollow bodies (“cavitation bubbles”) in fluids in the

    tissues

• Local Soft tissue swelling

  • Due to microtrauma

• Transient Pain

  • We are applying microtrauma, side effects are

    possible; these side effects are explained to the p

SWT INDICATIONS

Intensity → Energy per Square Area

• Low →

• Moderate →

• High →

• < 0.1 mJ/mm2

• 0.1-0.2 mJ/mm

• > 0.2 mJ/mm2

SWT Contraindications

• Bleeding conditions

  • hemorrhage

• Pacemakers

  • Near pacemakers

  • Application on the left and right shoulder, trapezius,

  • trigger points are contraindicated

  • LE is possible

• Medications that prolong blood clotting

  • Any problems with blood

• Children

  • They might not be able to tolerate due to its sound

• Pregnancy

  • Not in the abdomen, low back, pelvis, and hip

  • Other areas are okay

• Acute injuries

  • Not beneficial since we are inducing microtrauma to a traumatized area

SWT Documentation

• Modality

• Body part

• Patient position

• Parameters (such as intensity, power, wavelength, duration)

• Rationale

  • *Integrity of the skin in area treated, before and after

• SWT using small head on L Achilles tendon in prone c

  3,000 shocks, using 0.3 mj/mm2 to ↓ pain.

• SWT using big head on anterior aspect of R shoulder in supine c 2,000 impulses at 0.28 mj/mm2 to

  disintegrate calcific deposits & ↓ pain.

• SWT using small head on identified trigger points on B

  upper trapezius in sitting x 1.5 bars x 2,000 shocks x 15Hz to ↓ pain.

Pre Test

• The frequency of ultrasound is greater than the frequency audible to the human ear - True

• Ultrasound is produced via the direct piezoelectric effect - False

• You will select the pulse mode if the indication is to accelerate tissue healing - True

• The continuous mode of ultrasound is preferred if the goal of treatment is to decrease pain - True

• Application of ultrasound near the ends of long bones in children is discouraged - True

• Shockwave therapy causes localized microtrauma - True
  Acute injuries are treated with shockwave therapy to facilitate healing - False

• The pulse duration in shockwave therapy is extremely long to induce physiologic effects - False

• Compared to US, the depth of penetration of acoustic energy in human tissues from shockwave therapy is more superficial - False

• Shockwave therapy has no thermal effect - True

Break a 🦵

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